Question: What is the greatest common factor of $40$ and $24$ ? Another way to say this is: $\operatorname{gcf}(40, 24) = {?}$
Explanation: The greatest common factor is the largest number that is a factor of both $40$ and $24$ The factors of $40$ are $1$ $2$ $4$ $5$ $8$ $10$ $20$ , and $40$ The factors of $24$ are $1$ $2$ $3$ $4$ $6$ $8$ $12$ , and $24$ Thus, the greatest common factor of $40$ and $24$ is $8$. $\operatorname{gcf}(40, 24) = 8$